Is it possible to download ios7 beta on my iphone 4?

I have an iphone 4 and wondering if it was possible to download ios 7 beta on it.right now i have 6.1.3 on it. Do i need to downgrade the firmware first and then upgrade it again to ios 7 or can my iphone not download ios 7 at all. I have a gsm model btw.

if i can update to ios 7 beta, please leave instructions or links, thanks.

Yes, but without a $99 dev account all idevices will be disabled on or before july 22nd when the ios 7 beta 2 is released.
not work it without a dev account